There is no reason for not departing IFR.
At least two have been given earlier in this thread.
All these big "reckless", "foolhardy", "dangerous" words are simply silly. In the real world of departing an airfield that is not in a CTR and doesn't have radar there is absolutely no difference in the safety of departing VFR or IFR. Known traffic only extends to 2.5 miles from the ARP, there could easily be unknown traffic crossing the take-off path whichever set of rules you declare.
I fear that there is a considerable amount of prejudice and a considerable lack of knowledge and experience being shown in this thread, some from people who equate IFR with controlled airspace and some from people who haven't got there yet.
Maybe we can tone down the accusations if we want a reasonable discussion.
Will